Evaluación de Subproductos de Cloración y su efecto mutagénico en agua para consumo humano

Proyecto de Investigación Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Química. Centro de Investigación y de Servicios Químicos y Microbiológicos (CEQIATEC), Centro de Investigación en Protección Ambiental (CIPA), 2013Se investigó la presencia de subproductos de desinfección como trihalometanos (THMs) por medio de la técnica de microextracción en fase sólida (HEADSPACE / SPME Solid Fase Microextraction / GS-MS), utilizando un Cromatógrafo de Gases Varian 450 acoplado a Espectrómetro de Masas. Se analizaron en total 39 muestras de agua, provenientes de fuentes de agua subterránea (nacientes) administradas por la Municipalidad del Cantón Central de Cartago y agua de origen superficial (Plantas de tratamiento completo) dispensada por los sistemas de Tratamiento de AyA/Cantón Central de Cartago, y los Sistema de Tratamiento de AyA de Moravia, Guadalupe y Pavas, con un total de 156 subproductos determinados y cuantificados correspondiendo estos a: cloroformo, bromodiclorometano, dibromoclorometano y tribromoclorometano. En las muestras de agua de sistemas de tratamiento completo se encontró que de 80 subproductos analizados, 12 de estos superaron el máximo admisible de acuerdo al Reglamento Nacional de Calidad de Agua para consumo humano, mientras que de los acueductos abastecidos de aguas subterráneas administrados por la Municipalidad de Cartago, de 76 subproductos analizados solo uno de ellos superó el valor máximo permitido. Los trihalometanos encontrados de acuerdo a la Agencia Internacional de Investigación en Cáncer (por sus siglas en inglés IARC) se ubican en el grupo 2 B con evidencia de producir cáncer en animales. Se encontró gran variación de la presencia de estos subproductos en las muestras de agua de los abastecimientos que corresponden a agua con tratamiento completo (agua superficial tratada) correlacionando con lo reportado ya en la literatura, no obstante se reportó por primera vez la casi ausencia total de subproductos en cantidades que superen los máximos permitidos en aguas de origen subterráneo correlacionando con menor cantidad de carbono orgánico total, menor cantidad de cloro agregado (cloro combinado) y por ser acueductos más pequeños, menor cantidad de cloro residual. Con respecto a la formación de los subproductos, de acuerdo a la literatura, se pudo afirmar que la misma se ve favorecida con el aumento de la dosis de cloro (no necesariamente el cloro residual) y el aumento del tiempo de contacto agua-cloro, por cuanto el contenido de THMs a la salida de las plantas de tratamiento se incrementa posteriormente en muchos casos en la red, debido principalmente al mayor tiempo de contacto con la materia orgánica y con sustancias orgánicas de biofilmes en la red. De acuerdo a determinaciones anteriores en muestreos control de agua municipal el promedio de cloro residual de las plantas de tratamiento es de 1.1 mg/L y el de los sistemas de agua subterránea es de 0,6 mg/L

Towards Control and Oversight of SARS-CoV-2 Diagnosis and Monitoring through Multiplexed Quantitative Electroanalytical Immune Response Biosensors

The development of versatile and sensitive biotools to quantify specific SARS-CoV-2 immunoglobulins in SARS-CoV-2 infected and non-infected individuals, built-on the surface of magnetic microbeads functionalized with nucleocapsid (N) and inhouse expressed recombinant spike (S) proteins is reported. Amperometric interrogation of captured N- and S-specific circulating total or individual immunoglobulin (Ig) isotypes (IgG, IgM, and IgA), subsequently labelled with HRP-conjugated secondary antibodies, was performed at disposable single or multiplexed (8) screen-printed electrodes using the HQ/HRP/H2O2 system. The obtained results using N and in-house expressed S ectodomains of five SARS-CoV-2 variants of concern (including the latest Delta and Omicron) allow identification of vulnerable populations from those with natural or acquired immunity, monitoring of infection, evaluation of vaccine efficiency and even identification of the variant responsible for the infection

Oral fosfomycin for the treatment of lower urinary tract infections among kidney transplant recipients—Results of a Spanish multicenter cohort

Preliminary results of this study were presented at the 29th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), held in Amsterdam, The Netherlands, from 13 to 16 April, 2019 (oral communication O‐0699).Oral fosfomycin may constitute an alternative for the treatment of lower urinary tract infections (UTIs) in kidney transplant recipients (KTRs), particularly in view of recent safety concerns with fluroquinolones. Specific data on the efficacy and safety of fosfomycin in KTR are scarce. We performed a retrospective study in 14 Spanish hospitals including KTRs treated with oral fosfomycin (calcium and trometamol salts) for posttransplant cystitis between January 2005 and December 2017. A total of 133 KTRs developed 143 episodes of cystitis. Most episodes (131 [91.6%]) were produced by gram‐negative bacilli (GNB), and 78 (54.5%) were categorized as multidrug resistant (including extended‐spectrum β‐lactamase‐producing Enterobacteriaceae [14%] or carbapenem‐resistant GNB [3.5%]). A median daily dose of 1.5 g of fosfomycin (interquartile range [IQR]: 1.5‐2) was administered for a median of 7 days (IQR: 3‐10). Clinical cure (remission of UTI‐attributable symptoms at the end of therapy) was achieved in 83.9% (120/143) episodes. Among those episodes with follow‐up urine culture, microbiological cure at month 1 was achieved in 70.2% (59/84) episodes. Percutaneous nephrostomy was associated with a lower probability of clinical cure (adjusted odds ratio: 10.50; 95% confidence interval: 0.98‐112.29; P = 0.052). In conclusion, fosfomycin is an effective orally available alternative for treating cystitis among KTRs.This study was supported by Plan Nacional de I+D+i 2013‐2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016)—cofinanced by the European Development Regional Fund “A way to achieve Europe”; the Group for Study of Infection in Transplantation and the Immunocompromised Host (GESITRA‐IC) of the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC); and the Spanish Network for Research in Renal Diseases (REDInREN RD16/0009). MFR holds a research contract “Miguel Servet” (CP 18/00073) from the Spanish Ministry of Science, Innovation and Universities, Instituto de Salud Carlos III

Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population

Efficacy and Safety of Oral Fosfomycin for Asymptomatic Bacteriuria in Kidney Transplant Recipients: Results from a Spanish Multicenter Cohort

Current guidelines recommend against systematic screening for or treating asymptomatic bacteriuria (AB) among kidney transplant (KT) recipients, although the evidence regarding episodes occurring early after transplantation or in the presence of anatomical abnormalities is inconclusive. Oral fosfomycin may constitute a good option for the treatment of posttransplant AB, particularly due to the emergence of multidrug-resistant (MDR) uropathogens. Available clinical evidence supporting its use in this specific setting, however, remains scarce. We performed a retrospective study in 14 Spanish institutions from January 2005 to December 2017. Overall, 137 episodes of AB diagnosed in 133 KT recipients treated with oral fosfomycin (calcium and trometamol salts) with a test-of-cure urine culture within the first 30 days were included. Median time from transplantation to diagnosis was 3.1 months (interquartile range [IQR], 1.1 to 10.5). Most episodes (96.4% [132/137]) were caused by Gram-negative bacteria (GNB), and 56.9% (78/137) were categorized as MDR (extended‐spectrum β‐lactamase‐producing Enterobacterales [20.4%] and carbapenem‐resistant GNB [2.9%]). Rate of microbiological failure at month 1 was 40.1% (95% confidence interval [CI], 31.9% to 48.9%) for the whole cohort and 42.3% (95% CI, 31.2% to 54.0%) for episodes due to MDR pathogens. Previous urinary tract infection (odds ratio [OR], 2.42; 95% CI, 1.11 to 5.29; P value = 0.027) and use of fosfomycin as salvage therapy (OR, 8.31; 95% CI, 1.67 to 41.35; P value = 0.010) were predictors of microbiological failure. No severe treatment-related adverse events were detected. Oral fosfomycin appears to be a suitable and safe alternative for the treatment (if indicated) of AB after KT, including those episodes due to MDR uropathogens.This study was supported by Plan Nacional de I+D+i 2013‐2016 and Instituto de Salud Carlos III (ISCIII), Subdirección General de Redes y Centros de Investigación Cooperativa, Ministry of Science and Innovation, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016), and Spanish Network for Research in Renal Diseases (REDInREN RD16/0009) and cofinanced by the European Development Regional Fund entitled A way to achieve Europe. M.F.-R. holds a research contract (Miguel Servet, CP18/00073), from the Spanish Ministry of Science and Innovation, ISCIII.Peer reviewe

Local hydrological conditions influence tree diversity and composition across the Amazon basin

Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well-drained and potentially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of 443 1-ha non-flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1) tree alpha diversity, 2) the community-weighted wood density mean (CWM-wd) – a proxy for hydraulic resistance and 3) tree species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more evident in wetter forests, where diversity increases towards locations with well-drained soils. CWM-wd increased towards better drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients in Central-Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood density of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution